Growth

When each biome seed is planted or painted, it the tiles will be populated for a certain distance that depends on the Biome Size and the Growth parameters, with the Biome Separation controlling the space between each tile.

The growth can be either Fixed or Random, depending upon which tab is selected when the Add Biome button is clicked.

Fixed Growth

Using these settings, the biome will grow in specific directions according to the prescribed distances. The settings to the right will produce a sort of rounded diamond shaped growth pattern, with growth extending from the center in each direction to 70 percent of the biome size. It will not be a cube shape with flat north/south/east/west boundaries.

Random Growth

Using these settings, the growth will be random in each direction, at least 30% to a maximum of 70% of the biome size.

Again, keep in mind that the growth pattern will respect other tile conditions such as height and slope.